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Topic: Timing of feeding culture (Read 2330 times)

I have been feeding my emerging culture on a 12 hour schedule as directed by Ed Wood in his Italian Sourdough Cultures. If I am forced by circumstances to deviate from this schedule is it better to feed it earlier or later than 12 hours? Also, how much latitude do I have in deviating from the 12 hour schedule?

The 12 hours thing is just a guideline. You have to look at it. After feeding it will begin to perk up an start to bubble. But after a while it will begin to look worse, with liquid forming at the top and the bubbles flattening or gone. You want to feed more or less at it's peak. Once you see it starting to look worse, even a bit, it's definitely time to feed it again.

When you first remove the culture from the fridge, the feedings may be 12 hours, but then they will shorten and shorten, until it really peeks in just 2 or 3 hours.

Well, you can't keep it at 85F forever and feed it every few hours for the rest of your life...

Here's the deal: The culture is a bunch of organisms that just want to eat and reproduce. That's pretty much all they do. If there's food around, they eat it. Ths speed at which they eat is primarily a function of the temperature. The 2 different kinds of organism in a culture (yeast and lactobacilli) are affected by temperature differently, but regardless, the warmer it is, the faster both eat and reproduce. As is eats it gives off waste products. These are CO2 which makes bubbles, and various organic compounds such as alcohols, lactic acids and other yummy things. Once it's eaten all the food, it's also expelled a lot of waste and starts kind of swimming in it's own waste and gets nasty. It sounds kind of gross, but that's what fermentation is all about. After it has degraded it's environment, it doesn't just die off, but it does slow down alot. The truth is that you can keep a culture out at room temp for a few weeks at least, without feeding it or cleaning it up, and it will still live. But it will just get progressively nastier and nastier looking, with green liquid filling up the top of the container and the flour sinking to the bottom. Actually, if a sample is really old and not fed, it will start to smell like wine. It looks nasty, but I've had people close their eyes and just smell it and guess what it is and they guess wine everytime. No surprise, wine is fermented by yeast for long periods. It really looks dead at that point, but I've never had a culture not revive. I had one in the fridge unfed for 6 months, and it looked nasty as anything and then I fed it a few cycles and it looked bubbly and healthy.

When you are not using a culture, you store it in the fridge. It will slowly degrade and develop hooch (that green liquid). It could take a day, it could take 3 weeks but eventually that is what will happen. Now you want to use it. You have to feed it and bring it back from that dormant state before you put it in your dough. How long does that take? It's really depends. There's no set time. It could look great after 1 feeding and 5 hours, or it might take 5 feedings and 3 days. But eventually, it will happen. You are on it's schedule. As I said before, you know it's time to feed it when it starts to look worse. At hour 0 (you just fed it), it looks like a flat batter. At hour 3 there are some bubbles. At hour 5 there are few more bubbles . At hour 6, the bubbles are deflating and it's looking slimy on top. In other words, it got a little worse. It's peeked. Time to feed it. Now, it peeked but it hasn't peeked well. Hour 5 was it's peek, but still not that great. So you have to cycle again. The next peek should be faster AND better. The second time, that cycle may take 4 hours. Why? Going into round 2, there are more live ones and so the whole thing is going to go faster.

If the culture is really old and slimy, the first peek might not look like much at all. But the same rule applies. It's relative. As long as it looks better right now than it did 10 minutes ago, it can keep going. As soon as it looks worse than it did 10 minutes ago, it can be fed. You don't have to sit there and stare at it, but that's the general idea. If you wait too long to feed it, then it will start to die off and will require more cycles. This happens to me all the time. I keep missing the peeks because I've got other things to do, and it so takes days to get the culture ready. I would say that the 12 hour time is not really a rule, but rather an upper bound. If it's sat for 12 hours and kind of looks the same, with no peek at all, then you can just time it out at 12 hours and feed it then. But really if you get to know it you will see that there's always some discernable difference, and thus always something of a peek. I guess there's one other case. And that is that the peek is hour 0. You feed it and 10 minutes later it already looks worse. So it's like it peeked at the start. In that case, let it go a few hours. Maybe 4. It might pickup a bit. If not then go ahead and feed it again.

As far as temperature goes, I no longer culture it at 85. It will go faster at that temp, but I just don't bother much anymore. I just do it at room temp. It's slower but otherwise the same. The only time you really have to do it at 85 is if the culture is like 6 months old. Otherwise, it should come back in a few feedings.

The good news is that there really is no way to screw this up. It's pretty hard to kill and you can always start over. The only real way to kill it is to contaminate it with a competing sample.

Thanks for your very informative response. I appreciate the time you took to write to me. I have printed out your reply as it will take me some time to digest all of it. Here's my remaining (?) question: In the Ed Wood's booklet, he says to refrigerate when the bubbles flow up to the top of the jar. While mine are showing good life, they haven't done this so I keep on feeding. Your thoughts.

the truth is it doesn't really matter that much. If it's in good shape when it goes in the fridge and you use it in the next week, it will probably revive in just a few hours. If it's not all bubbly and fresh, it will just take longer. Either way, after a week or two in the fridge, it's going to fall off and take a while no matter what. No matter what, though, it will come back, it's just a matter of time.

I think Jeff and Bakerbill are talking about different things. Perhaps I am wrong, but Bill is talking about the initial activation of a dehydrated culture from sourdo.com. If so, then it is absolutely necessary to keep the culture in or near the recommended temperature range. At this point the culture is very weak and subject to contamination. I don't think it is necessary to rigidly follow the 12-hour feeding schedule, but until it is fully activated, you want to avoid letting it run out of food or getting too cool or hot.

Once it is fully activated, you can store it in the fridge and do your activations at room temp.

Yes, I am talking about initial activation. Thanks for that clarification. I will continue (it's been five days since I started) and hopefully the culture will flow to the top of the jar. This is my second attempt; I believe my first effort died because of excess temperature as I look back on it. This one is going better. I appreciate the support and patience the forum has had with my efforts.